(Invited) Reliability of Polycrystalline Silicon Thin-Film Transistors on the Glass Substrate

Abstract

We have investigated electrical characteristics of laser-crystallized polycrystalline silicon thin film transistors (poly-Si TFTs) under various stresses such as bias, temperature, light illumination. The threshold voltage of short channel TFT (LCH=1.5μm) was significantly shifted to negative direction due to bias temperature stress (ΔVTH = -3.75V) compared with that of long channel TFT (ΔVTH = -0.32V) at 100{degree sign}C. We have also investigated the effects of light illumination on the laser-crystallized poly-Si TFT. In order to improve the reliability of laser-crystallized poly-Si TFT, a novel multiple-channel structure was proposed and fabricated without any additional processes. In addition, in order to enhance the electric characteristics and stability of alternating magnetic-field-enhanced rapid thermal annealing (AMFERTA) poly-Si TFTs, we have employed the NH3 plasma pretreatment prior to crystallization process. The NH3 plasma pretreatment process could effectively improve the reliability of AMFERTA poly-Si TFTs.